Climate change, with its growing impact on agriculture, demands resilient, sustainable, and resource-efficient food production systems. Edible fungi, traditionally valued for their nutritional and culinary qualities, are increasingly recognised for their potential in sustainable crop diversification. While Agaricus bisporus (button mushroom) dominates global production, species with higher adaptability and lower environmental footprints are gaining attention. Among these, Pleurotus ostreatus (commonly known in Latin America as “orellana”) stands out as a promising alternative due to its ability to grow on various agro-industrial residues, rapid production cycles, and suitability for small- and medium-scale farming. This study developed and assessed cultivation protocols for substrate preparation, harvesting, postharvest handling, and transportation to enhance product quality and shelf life. The proposed procedures incorporated agricultural by-products such as coffee husks, sawdust, and sugarcane bagasse, alongside detailed recommendations for sterilisation, inoculation, and incubation. Harvesting and postharvest strategies emphasised optimal timing, humidity control, and packaging methods to minimise mechanical damage, microbial contamination, and senescence. Implementing these guidelines resulted in higher yields, improved texture, and extended fruiting-body freshness, thereby increasing their commercial value. Systematising these practices reinforces P. ostreatus as a sustainable alternative crop under climate change scenarios, contributing to rural income diversification and food security. Future research should focus on scaling up under varied agroecological conditions, assessing energy efficiency in controlled environments, and exploring biodegradable packaging solutions to further strengthen sustainability across the value chain.